Sea Rise and Global Warming

Sea level rise is already redrawing coastlines around the world. What happens when the coast retreats through a major city? We look at how the world map will change in the year 2100, and what coastal cities can do to defend themselves. Infographic: Sea Level Rise and Global Warming, Sea level is rising—and at an accelerating rate—especially along the U.S. East Coast and Gulf of Mexico.

Why are the East Coast and Gulf of Mexico hotspots of sea level rise?Global average sea level has increased 8 inches since 1880. Several locations along the East Coast and Gulf of Mexico have experienced more than 8 inches of local sea level rise in only the past 50 years.

The rate of local sea level rise is affected by global, regional, and local factors.Along the East Coast and Gulf of Mexico, changes in the path and strength of ocean currents are contributing to faster-than-average sea level rise.In parts of the East Coast and Gulf regions, land is subsiding, which allows the ocean to penetrate farther inland.

How quickly is land ice melting?Shrinking land ice — glaciers, ice caps, and ice sheets — contributed about half of the total global sea level rise between 1972 and 2008, but its contribution has been increasing since the early 1990s as the pace of ice loss has accelerated.Recent studies suggest that land ice loss added nearly half an inch to global sea level from 2003 to 2007, contributing 75 to 80 percent of the total increase during that period.

Why is there such a large range in sea level rise projections?The long-term rate of global sea level rise will depend on the amount of future heat-trapping emissions and on how quickly land ice responds to rising temperatures.Scientists have developed a range of scenarios for future sea level rise based on estimates of growth in heat-trapping emissions and the potential responses of oceans and ice. The estimates used for these two variables result in the wide range of potential sea level rise scenarios.

How high and how quickly will sea level rise in the future?Our past emissions of heat-trapping gases will largely dictate sea level rise through 2050, but our present and future emissions will have great bearing on sea level rise from 2050 to 2100 and beyond.

Even if global warming emissions were to drop to zero by 2016, sea level will continue to rise in the coming decades as oceans and land ice adjust to the changes we have already made to the atmosphere.

The greatest effect on long-term sea level rise will be the rate and magnitude of the loss of ice sheets, primarily in Greenland and West Antarctica, as they respond to rising temperatures caused by heat-trapping emissions in the atmosphere.

The frozen continent of Antarctica contains the vast majority of all freshwater on Earth. Now that ice is melting at an accelerating rate, in part because of climate change. What does this transformation mean for coastal communities across the globe? William Brangham reports from Antarctica on the troubling trend of ice loss and how glaciers can serve as a climate record from the past

A damning report from the the Intergovernmental Panel on Climate Change has put the world on the path to a ‘climate catastrophe’ as global warming nears 3C. As scientists say global warming must be limited to 1.5 C, we investigate if it’s too late to turn back. Newsnight is the BBC’s flagship news and current affairs TV programme – with analysis, debate, exclusives, and robust interviews.

Infographic: Western Wildfires and Climate ChangeRising temperatures are increasing wildfire risk throughout the Western U.S.

Panel 1: Wildfires and Wildfire SeasonThe number of large wildfires — defined as those covering more than 1,000 acres — is increasing throughout the region. Over the past 12 years, every state in the Western U.S. has experienced an increase in the average number of large wildfires per year compared to the annual average from 1980 to 2000.Wildfire season is generally defined as the time period between the year’s first and last large wildfires. This infographic highlights the length of the wildfire season for the Western U.S. as a region. Local wildfire seasons vary by location, but have almost universally become longer over the past 40 years.Panel 2: Rising Temperatures and Earlier SnowmeltTemperatures are increasing much faster in the Western U.S. than for the planet as a whole. Since 1970, average annual temperatures in the Western U.S. have increased by 1.9° F, about twice the pace of the global average warming.Scientists are able to gauge the onset of spring snowmelt by evaluating streamflow gauges throughout the Western U.S. Depending on location, the onset of spring snowmelt is occurring 1-4 weeks earlier today than it did in the late 1940s.Panel 3: Future ProjectionsThe projected increase in annual burn area varies depending on the type of ecosystem. Higher temperatures are expected to affect certain ecosystems, such as the Southern Rocky Mountain Steppe-Forest of central Colorado, more than others, such as the semi-desert and desert of southern Arizona and California. Every ecosystem type, however, is projected to experience an increase in average annual burn area.The range of projected temperature increases in the Western U.S. by mid-century (2040 – 2070) represents a choice of two possible futures — from one in which we drastically reduce heat-trapping emissions (the projected low end of a lower emissions pathway) to a future in which we continue with “business as usual” (the projected high end of a higher emissions pathway).

Climate change is the greatest global threat to coral reef ecosystems, and scientific evidence now clearly indicates that the Earth’s atmosphere and ocean are warming. A changing climate is affecting coral reef ecosystems through sea level rise, changes to the frequency and intensity of tropical storms, and altered ocean circulation patterns. When combined, all of these impacts dramatically alter ecosystem function, as well as the goods and services coral reef ecosystems provide to people around the globe. Our infographic explains the process, from sea-level rise to ocean acidificiation. Source: https://www.noaa.gov/multimedia/infographic/infographic-how-does-climate-change-affect-coral-reefs